Commented Unassigned: Bundling throws error "Cannot use a leading .. to exit above the top directory." [27781]

I'm new to bundling, but I followed the directions and when loading my page, the following server error displays:

Bundling throws error "Cannot use a leading .. to exit above the top directory."

I've checked my web page code, and nowhere do I reference any files using ../. They are all ~/ syntax.

Where have I gone wrong, or how do I troubleshoot this? if I disable bundling, then the error disappears.
Comments: I experience this problem too with the latest version of AjaxControlToolkit (version: 15.1.1.100). Here are steps to rerpoduce this problem: 1) Bundling is enabled, 2) Place ValidatorCalloutExtender on usercontrol, 3) Attached this usercontrol to the page which path contains more subfolders than path to the usercontrol. For example: /UCTest.ascx /UI/Default.aspx One workaround is to create some additional subfolders for usercontrols. For example using this structure works properly: /UserCtontrols/UCTest.ascx /UI/Default.aspx But it is really silly solution for some complex projects. I'd appreciate better solution. I attached sample project to reproduce this issue.